XP pro looses network connections on re-boot

I have XP Pro installed on a desktop machine using dial-
up connection. Everything works OK. Have set up a peer to
peer network with my laptop running W98SE, network works
fine, ICS works OK.
However, when I restart the XP pro machine, the network
seems to disappear.
The only way I can reset the network, is to set up the
home network again and run the wizard.
I have disabled "simple file sharing" to improve security.
I am running ZoneAlarm but have configured trusted zones
to allow normal communication on the network.
This problem only seems to have occured since upgrading
from ME.
Have tried dropping the LAN connection from the bridge
and then reinstating, this solves the network problem
until the next re-boot.
As yet I
have been unable to rectify the problem. Any suggestions?